feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/opencv-4.5.4/modules/videoio/cmake/detect_openni2.cmake

@@ -0,0 +1,47 @@
+# --- OpenNI2 ---
+
+if(NOT HAVE_OPENNI2)
+  set(paths "${OPENNI2_DIR}")
+  if(MSVC AND X86_64)
+    list(APPEND paths ENV OPENNI2_INCLUDE64 ENV OPENNI2_LIB64 ENV OPENNI2_REDIST64)
+  else()
+    list(APPEND paths ENV OPENNI2_INCLUDE ENV OPENNI2_LIB ENV OPENNI2_REDIST)
+  endif()
+
+  # From SDK
+  find_path(OPENNI2_INCLUDE "OpenNI.h"
+    PATHS ${paths}
+    PATH_SUFFIXES "Include"
+    NO_DEFAULT_PATH)
+  find_library(OPENNI2_LIBRARY "OpenNI2"
+    PATHS ${paths}
+    PATH_SUFFIXES "Redist" "Lib"
+    NO_DEFAULT_PATH)
+
+  if(OPENNI2_LIBRARY AND OPENNI2_INCLUDE)
+    set(HAVE_OPENNI2 TRUE)
+    set(OPENNI2_INCLUDE_DIRS "${OPENNI2_INCLUDE}")
+    set(OPENNI2_LIBRARIES "${OPENNI2_LIBRARY}")
+  endif()
+endif()
+
+if(NOT HAVE_OPENNI2)
+  # From system
+  find_path(OPENNI2_SYS_INCLUDE "OpenNI.h" PATH_SUFFIXES "openni2" "ni2")
+  find_library(OPENNI2_SYS_LIBRARY "OpenNI2")
+
+  if(OPENNI2_SYS_LIBRARY AND OPENNI2_SYS_INCLUDE)
+    set(HAVE_OPENNI2 TRUE)
+    set(OPENNI2_INCLUDE_DIRS "${OPENNI2_SYS_INCLUDE}")
+    set(OPENNI2_LIBRARIES "${OPENNI2_SYS_LIBRARY}")
+  endif()
+endif()
+
+if(HAVE_OPENNI2)
+  file(STRINGS "${OPENNI2_INCLUDE_DIRS}/OniVersion.h" ver_strings REGEX "#define +ONI_VERSION_(MAJOR|MINOR|MAINTENANCE|BUILD).*")
+  string(REGEX REPLACE ".*ONI_VERSION_MAJOR[^0-9]+([0-9]+).*" "\\1" ver_major "${ver_strings}")
+  string(REGEX REPLACE ".*ONI_VERSION_MINOR[^0-9]+([0-9]+).*" "\\1" ver_minor "${ver_strings}")
+  string(REGEX REPLACE ".*ONI_VERSION_MAINTENANCE[^0-9]+([0-9]+).*" "\\1" ver_maint "${ver_strings}")
+  set(OPENNI2_VERSION "${ver_major}.${ver_minor}.${ver_maint}")  # informational
+  ocv_add_external_target(openni2 "${OPENNI2_INCLUDE_DIRS}" "${OPENNI2_LIBRARIES}" "HAVE_OPENNI2")
+endif()